Download (PDF)

10NCEE
Tenth U.S. National Conference on Earthquake Engineering
Frontiers of Earthquake Engineering
July 21-25, 2014
Anchorage, Alaska
STATION CHALLENGES ON SEISMIC
QUALIFICATION OF STRUCTURES,
SYSTEMS AND COMPONENTS IN
CANADIAN NUCLEAR POWER PLANTS
A. Dar1, D. Konstantinidis2, W. W. El-Dakhakhni3
ABSTRACT
The Fukushima Daiichi accident during the 2011 Tohoku, Japan, earthquake and tsunami
prompted the world nuclear industry, to focus on the assessment of Beyond Design Basis (BDB)
vulnerabilities of Nuclear Power Plants (NPPs). All the NPPs in Canada are situated on the east
coast whereas the Canadian standards recommend a generic Design Basis Earthquake (DBE)
response spectrum based on west coast (California) records having entirely different frequency
content from the credible east coast events. Over the frequency range of interest, the spectral
accelerations of the DBE of a typical existing east coast Canadian NPP are found to be higher
than those of the prescribed BDB event based on the east coast records. The concept of risk
based design is not addressed in the Canadian standards. Neglect of issues such as seismic
interaction at the design stage brings down not only the BDB capacity but also the design
capacity adversely affecting the seismic risk. Answers to some of these challenges are found to
be scattered all across the literature but not captured in one place by any design guide, regulation
or standard. Various reports from different agencies, seismic margin studies and the regulatory
requirements in the post-Fukushima environment have many commonalities and differences
resulting in duplication of work related to the BDB seismic assessment of a nuclear generating
station in Canada. This paper is an attempt to suggest a path forward through complexities,
overlaps and gaps in the process of seismic qualification including BDB assessment of the east
coast Canadian NPPs and to recommend resolutions in this regard with the examples of two
plants located at the Bruce Nuclear Generating Station site in Canada.
1
Tecnhical Advisor, Engineering, Bruce Power, 177 Tie Road, Tiverton, ON, N0G 2T0, Canada
Assistant Professor, Dept. of Civil Engineering, McMaster University, Hamilton, ON, L8S 4L7, Canada
3
Associate Professor, Dept. of Civil Engineering, McMaster University, Hamilton ON, L8S 4L7, Canada
2
Dar A, Konstantinidis D, El-Dakhakhni WW. Station challenges on seismic qualification of structures, systems and
components in Canadian nuclear power plants. Proceedings of the 10th National Conference in Earthquake
Engineering, Earthquake Engineering Research Institute, Anchorage, AK, 2014.
10NCEE
Tenth U.S. National Conference on Earthquake Engineering
Frontiers of Earthquake Engineering
July 21-25, 2014
Anchorage, Alaska
Station Challenges on Seismic Qualification of Structures, Systems and
Components in Canadian Nuclear Power Plants
A. Dar1, D. Konstantinidis2, W. W. El-Dakhakhni3
ABSTRACT
The Fukushima Daiichi accident during the 2011 Tohoku, Japan, earthquake and tsunami
prompted the world nuclear industry, to focus on the assessment of Beyond Design Basis (BDB)
vulnerabilities of Nuclear Power Plants (NPPs). All the NPPs in Canada are situated on the east
coast whereas the Canadian standards recommend a generic Design Basis Earthquake (DBE)
response spectrum based on west coast (California) records having entirely different frequency
content from the credible east coast events. Over the frequency range of interest, the spectral
accelerations of the DBE of a typical existing east coast Canadian NPP are found to be higher than
those of the prescribed BDB event based on the east coast records. The concept of risk based
design is not addressed in the Canadian standards. Neglect of issues such as seismic interaction at
the design stage brings down not only the BDB capacity but also the design capacity adversely
affecting the seismic risk. Answers to some of these challenges are found to be scattered all across
the literature but not captured in one place by any design guide, regulation or standard. Various
reports from different agencies, seismic margin studies and the regulatory requirements in the
post-Fukushima environment have many commonalities and differences resulting in duplication of
work related to the BDB seismic assessment of a nuclear generating station in Canada. This paper
is an attempt to suggest a path forward through complexities, overlaps and gaps in the process of
seismic qualification including BDB assessment of the east coast Canadian NPPs and to
recommend resolutions in this regard with the examples of two plants located at the Bruce Nuclear
Generating Station site in Canada.
Introduction
All NPPs in Canada are located on the east coast of the North American continent, including the
Bruce site at Tiverton, Ontario, having two nuclear generating stations known as Bruce A and
Bruce B. Out of the two, Bruce A was constructed first, more than three decades ago, without a
DBE but with some of the containment structures designed for the lateral seismic load derived as
a percentage of the vertical load. This was followed by the construction of the second station
Bruce B, designed for a DBE, based on the Newmark, Blume and Kapoor (NBK) spectrum [1],
recommended by the USNRC Regulatory Guide 1.60 [2]. The seismic capacity of Bruce A was
later on assessed in the early 2000s in accordance with the Seismic Margin Assessment (SMA)
1
Tecnhical Advisor, Engineering, Bruce Power, 177 Tie Road, Tiverton, ON, N0G 2T0, Canada
Assistant Professor, Dept. of Civil Engineering, McMaster University, Hamilton, ON, L8S 4L7, Canada
3
Associate Professor, Department of Civil Engineering, McMaster University, Hamilton, ON, L8S 4L7, Canada
2
Dar A, Konstantinidis D, El-Dakhakhni WW. Station challenges on seismic qualification of structures, systems and
components in Canadian nuclear power plants. Proceedings of the 10th National Conference in Earthquake
Engineering, Earthquake Engineering Research Institute, Anchorage, AK, 2014.
methodology outlined in [3] for the Review Level Earthquake (RLE) based on the latest research
[4]. The frequency contents of the DBE and the RLE are drastically different since the former is
based on west coast records and the latter is derived from east coast records [5]. A detailed
discussion on the history of seismic design at Bruce site can be found in [5]. Some of the NPPs
in Canada have also undergone Seismic Probabilistic Risk Assessment (SPRA) leading to High
Confidence Low Probability of Failure (HCLPF) seismic capacity expressed in terms of Peak
Ground Acceleration (PGA).
The seismic event at the Japanese NPP at Fukushima Daiichi in 2011 triggered the
process of BDB evaluations of NPPs in Canada. By this time the Canadian regulation S-294 [6]
was in force and the work on the SPRAs of the Canadian NPPs had already begun or was at an
advanced stage. The new regulatory requirements in the post Fukushima environment focused on
the issues not addressed before, such as the evaluation of fuel bays, employment of emergency
mitigating equipment etc. The focus of the Fukushima upgrades was to assess and mitigate the
BDB vulnerability of a Canadian NPP, thus highlighting the requirement of establishing the
seismic margin of such plants over and above their design basis. The plants without a DBE, but
evaluated for the RLE by the SMA methodology about a decade ago, scored better in this regard
since their seismic capacities were known, whereas the capacities (and hence the BDB seismic
margins) of the DBE based plants remained unknown. This gave rise to a debate on the
requirement of SMA of a DBE based NPP despite having SPRA. However, the credible event
response spectrum considered by the SPRA process is based on the east coast records having
much lesser spectrum accelerations than those of the DBE of a typical east coast Canadian NPP
over the frequency range of interest which is typically between 1 to 10 Hz. Questions on how to
deal with a NPP with the DBE response spectrum richer than the credible event spectrum have
been answered in the EPRI report 1025287 [7]. Nevertheless, many other questions such as how
to establish the design basis of new emergency mitigating equipment or of new systems and
components required by the Fukushima upgrades remain unanswered. This paper establishes a
road map through various design guides, applicable standards, seismic qualification methods and
regulatory requirements to meet the station challenges related to the seismic qualification of
structures, systems and components of Canadian NPPs in the post Fukushima environment.
Review of Design Basis and Seismic Margin
In order to understand the seismic qualification process ranging from the design basis
qualification to the BDB evaluation, two nuclear generating stations are considered here as
examples: Bruce A and Bruce B at Tiverton, Ontario, Canada. These examples are similar to the
other stations in Ontario explained in detail in [8]. The frequency content difference between the
spectra of the DBE and the east coast credible event is quite similar to the example given in the
EPRI report 1025287 [7]. The challenges posed by the frequency contents of the above spectra at
Bruce stations are not very far from the realities of the other east coast plants in North America
subject to high frequency hazards.
DBE Spectrum and ENA Spectrum
Figure 1 shows two response spectra anchored at 0.05g PGA representing the DBE of Bruce B
based on USNRC Regulatory Guide 1.60 [2] and the generic DBE recommended by the
Canadian Standard CSA N289.3 [9]. Both the spectra are based on California records and are
considered equivalent here, because of their strong similarity. Also shown is the east coast
spectrum recommended in [4], popularly known as the East North American (ENA) spectrum. It
is evident from Fig. 1 that the DBE is conservative over the low frequency range, typically from
1 to 10 Hz whereas it is deficient beyond 10 Hz in comparison with the ENA spectrum. However
since the frequency range of interest at Bruce site lies within the range of 1 to 10 Hz [5], the
DBE is considered to be stronger than the credible event represented by the ENA spectrum. High
frequency content is not captured in the DBE and the CSA spectra, considered important only for
the components susceptible to high frequency vibrations [7]. The Canadian standards CSA
N289.3 [9] and CSA N289.1 [10] recommend the DBE to be represented by a mean Uniform
Hazard Response Spectrum (UHRS) with 1x10-4 probability of exceedance per annum with the
exception of the fact that for some of the existing plants the probability of exceedance of 1x10-3
per annum has been accepted by the regulator.
Acceleration (g)
1
0.1
0.01
DBE (BB) at 0.05g
ENA at 0.05g
0.001
CSA at 0.05g
0.0001
0.01
0.1
1
10
100
Frequency (Hz)
Figure 1. Comparison of DBE [5], CSA [9] and ENA [4] horizontal response spectra, anchored
at 0.05g with 5% damping.
Acceleration (g)
1
0.1
DBE (BB) at 0.05g
0.01
RLE (BA) at 0.15g
ENA at 0.15g
0.001
0.1
1
10
100
Frequency (Hz)
Figure 2. Comparison of horizontal response spectra DBE [5] anchored at 0.05g PGA with
RLE [5] and ENA [4], anchored at 0.15g PGA with 5% damping.
Review Level Earthquake (RLE) and Seismic Margin
The SMA methodology outlined in NP-6041 [3] establishes a success path in order to bring a
reactor to and maintain its safe shutdown state during and after a prescribed seismic event known
as RLE, represented by an 84 percentile 1x10-4 UHRS, having 0.15g PGA for Bruce A. Various
structures, systems and components essential to maintain the success path have been evaluated
and modified if necessary for the RLE at Bruce A. The PGA of RLE is required to be
significantly higher than that of the DBE in order to identify the BDB vulnerabilities of a station.
Figure 2 compares the DBE of Bruce B and RLE of Bruce A with the ENA spectrum. RLE and
ENA are anchored at 0.15g PGA whereas the DBE is anchored at 0.05g PGA. It should be noted
that despite the high PGA, the Bruce A RLE is more or less the same as the low PGA DBE up to
2.5 Hz frequency. Looking at the similarity in the dynamic characteristics of various structures at
both the stations [5], it can be concluded on the basis of the ratio of the PGAs of RLE and DBE,
that the seismic margin of Bruce A is 3 times the design basis of Bruce B. Canadian Standards
[9, 10] define the beyond design basis event as Checking Level Earthquake (CLE) with mean
values having probability of exceedance as 1x10-5 or 1x10-4 per annum for new plants. CLE and
RLE can be considered practically equivalent to each other since the earthquake records do not
have symmetrical distribution and the mean values fall between 70th and 90th percentile for the
distribution of Canadian earthquakes [11].
Table 1.
Applicability of various seismic hazards on the same site
Acronym Seismic Event
Design/Evaluation
stresses for
mechanical systems
DBE
Design Basis Earthquake
SDE
Applicability
PGA
ASME service level C
Bruce B
0.05g
Site Design Earthquake
(1/2 of DBE)
ASME service level B
Bruce B
0.025g
RLE
Review Level
Earthquake
ASME service level D
Bruce A
0.15g
SSE
Safe Shut Down
Earthquake
ASME service level D
Testing*
NA+
OBE
Operating Basis
Earthquake
ASME service level B
Testing*
NA+
NBCC
National Building Code
of Canada
Non-nuclear
structures
NA+
GMRS
NA+
Ground Motion
ASME service level D
Fukushima
Response Spectrum
evaluations
*Reported in the seismic test reports from the United States of America.
+
Not applicable
NA+
Station Challenges on Design Basis and Beyond Design Basis Seismic Events
For the two stations at the same site, many seismic events are applicable depending on the
requirement. Table 1 lists the types of seismic events along with their applicability in different
circumstances. While the DBE, RLE, SDE are all related to the Canadian environment, a seismic
engineer has to be aware of the hazards considered in US, such as SSE and OBE, which are the
basis of testing of various components imported from across the border.
Design Basis More Conservative than the Beyond Design Basis (BDB) Event
While considering a BDB event, a general assumption prevails that it would be more
conservative than the design basis. However, for the east coast plants, it is not true. The SPRA
study [12] calculates the seismic responses of Bruce B structures based on the mean 1x10-4
UHRS established by considering the data for 1x10-4 and 1x10-5 hazards [13]. USNRC guide
1.208 [14] recommends establishing a Ground Motion Response Spectra (GMRS) utilized by
EPRI report 1025287 [7] for Fukushima evaluations. Figure 3 shows the comparison between
GMRS, Bruce B DBE and the new mean 1x10-4 UHRS utilized in SPRA study.
0.3
1x10-4 UHRS (East Coast)
GMRS
0.25
DBE (West Coast)
Adjusted DBE = 1.33*DBE
Acceleration (g)
0.2
0.15
0.1
0.05
0
0.1
1
Frequency (Hz)
10
100
Figure 3. Horizontal response spectra representing DBE [5] with mean 1x10-4 UHRS [12],
GMRS [14] and adjusted DBE (to incorporate SSE) at 5% damping.
EPRI report 1025287 [7] focuses on the frequency range from 1 to 10 Hz and
recommends that if the Safe Shut Down Earthquake (SSE) or HCLPF spectrum is higher than the
GMRS between 1 to 10 Hz, no further evaluation is necessary except for the high frequency
susceptible components. SSE is applicable to the US plants subject to the ASME service level D
[15] allowable stresses for mechanical components (reactor, piping, valves etc.) whereas the
Canadian plants subject to the DBE are designed for ASME service level C stresses [15].
Approximate ratio between the two service level stresses (D and C) is 1.33. Hence in order to
obtain a true comparison for the mechanical components, the DBE of Bruce B is scaled up by
1.33 addressed as adjusted DBE in Fig. 3. This adjusted DBE is found to be higher than the
GMRS up to 8 Hz frequency, closed to the applicable frequency range, implying that the HCLPF
capacities of such components would even be higher. Hence it can be concluded by inspection
that on the basis of hazard comparison for Bruce B, only high frequency susceptible components
need be evaluated for Fukushima evaluation.
Since the GMRS corresponds to the lower probability of exceedance than the DBE, it is
considered here as a BDB spectrum. The question arises from the above that are we really
comparing the design with a BDB event or a credible event? Figure 3 demonstrates that the
design basis is found to be higher than the GMRS over the frequency range of interest and hence
the term BDB is not truly reflective of its meaning. The DBEs of the Canadian east coast plants
are conservative over the prescribed frequency range and it would be over conservative to
establish a hazard above the design basis of the east coast plants. Hence it can be concluded that
for the east coast plants, the term Beyond Credible event Basis (BCB) should be incorporated
rather than the term BDB to describe the capacity above design basis.
GMRS and RLE
Figure 4 shows comparison between the GMRS with the RLE of Bruce A along with the mean
1x10-4 and 1x10-5 hazards [13]. It is evident from Fig. 4 that the RLE of Bruce A is above the
GMRS on the entire range of frequencies leading to the conclusion that the seismic capacity of
Bruce A station is well beyond the Fukushima evaluation requirements.
0.7
1x10-4
1x10-5
GMRS
RLE
0.6
Aceleration (g)
0.5
0.4
0.3
0.2
0.1
0
0.1
1
Frequency (Hz)
10
100
Figure 4. Horizontal response spectra representing RLE [5] with mean 1x10-4 and mean 1x10-5
UHRS [13] and GMRS [14] at 5% damping.
Beyond Design Basis Evaluation and Canadian Standards
CSA standards [9, 10] consider the CLE as either mean 1x10-5 or mean 1x10-4 hazard utilized for
the beyond design basis evaluation of new plants. For the seismic margin assessment of
Canadian plants, 1x10-4 is the accepted probability of exceedance [8]. Clause 8 of CSA N289.3
[9] mandates evaluation of a NPP subject to the CLE in order to establish its BDB capacity.
According to Fig 3, the mean 1x10-4 UHRS (or CLE per above discussion) is well below the
DBE and hence according to the Canadian standards the BDB event’s spectral accelerations are
much lower than those of the DBE over the prescribed frequency range. Clarification of the
phrase “beyond design basis” in Canadian standards is warranted in this regard for the evaluation
of systems and components in an existing east coast plant.
Vertical Spectra and Their Adverse Impact on the Seismic Risk
The Canadian standards recommend the vertical response spectral accelerations to be two third
of the horizontal acceleration of the generic DBE spectrum at the corresponding frequencies with
the exception of the site specific hazard without any further guidance. The USNRC guide 1.208
[14] does not recommend any constant multiplication factor but recommends an entirely
different procedure to derive it from the horizontal response spectrum for a typical east coast
hazard. In a DBE based environment, the designers of a new system in an existing plant end up
designing for much lesser vertical acceleration than what is required for the new hazard having
adverse impact on the seismic risk.
Station Challenges on Evaluation of Systems and Components
After establishing the evaluation hazard, a typical SPRA study goes on further to establish
fragilities of the SSCs leading to the plant fragility and to the seismic risk. There are various
issues in this regard that lead to un-necessarily high seismic risk.
Seismic Interaction – Assessed Plants Score Better than the Designed Plants
A seismically qualified component is not allowed to have any other system or component (such
as a suspended light or an unreinforced concrete block wall) that can interact with it in case of a
seismic event. This aspect is very well dealt with in NP-6041 [3] for seismic margin assessment
but completely missed by the design codes. Hence the plants that did not have the DBE but were
assessed for the RLE score much better than the designed plants on this account. Seismic
interaction is warranted to be mandated by the Canadian standards at the design stage in order to
reduce the seismic risk. For the new plants it is covered by the clause 8 of CSA N289.3 [9] but
clarity is required in case of new components in an existing plant.
Vertical Amplification
For a typical east coast hazard, the amplification of vertical component of the ground response
spectrum is found to be much more than the horizontal because the vertical frequencies of the
buildings are found to be above 20Hz in general. The high frequency susceptible components
attached to a shear wall would contribute much more to the seismic risk than the ones anchored
to a long beam. Canadian standards are warranted to include remedies to such situations in this
regard.
Risk Based Design and S-294
The regulation S-294 [6] mandates the assessment of seismic risk of Canadian NPPs at regular
intervals. The design standards such as N285.0 [16] do not mandate the incorporation of risk at
the design stage resulting in varying seismic risk of different components. This adversely affects
the BDB capacity of newly designed components. One of the ways of incorporating risk in the
design of a component can be to evaluate it (in addition to the design for the applicable standard)
for the RLE with Conservative Deterministic Failure Margin Method (CDFM) in accordance
with NP-6041 [3]. This is incorporated in the clause 8 of CSA N289.3 [9] for the new plants.
However, the same should be applicable to the new systems and/or components in the existing
plants in order to mitigate the seismic risk. The details regarding the process of SMA and CDFM
method can be found in [17].
Emergency Mitigating Equipment / Systems
Incorporation of emergency mitigating equipment or systems such as fire trucks, additional water
pumps, piping etc. is a new post-Fukushima regulatory requirement. Piping being a pressure
retaining component is governed by the standard N285.0 [16]. The operating license of both the
stations Bruce A and B does not incorporate the current versions of CSA N289.3 [9] and CSA
N289.1 [10]. The older versions of these two standards do not recognize the CDFM method
utilized by NP-6041 [3]. Since the license is restricted to the design, the components required for
the BDB consideration are beyond license and hence they can be designed in accordance with
the CDFM method. However since Bruce B station does not have an RLE, such components are
designed for the DBE with ASME service level C stresses which is very conservative. The
regulatory document R-77 [18] assigns allowable stresses with ASME service level conditions to
an event in accordance its probability of occurrence. It considers an event with 1 in 10000
probability as an extremely rare event and assigns ASME service level D stress to it as the
allowable stress. A BDB event has a lower probability of occurrence (typically 1x10-4) than the
design basis and hence the allowable stresses can be taken from R-77 [18].
The emergency mitigating equipment or systems can be designed for the envelope of the
DBE and GMRS for Bruce B station in accordance with the CDFM methodology outlined in NP6041 [3] subject to ASME service level D stresses.
Conclusions
It is concluded that the mitigation of the seismic risk at the design stage is not covered by the
Canadian standards. Provisions regarding beyond design basis evaluation of the new plants are
required to be extended to the design of new systems and components in existing plants. In this
regard, for the east coast NPPs in Canada, the phrase “Beyond Design Basis” should be replaced
by “Beyond Credible Event Basis” since the design basis response spectra of such plants exceed
their GMRS over the general frequency range of interest. The emergency mitigating equipment
or systems, if required, can be designed for the envelope of the DBE and GMRS for the DBE
based plants by the CDFM method.
It is not necessary to carry out the SMA of a DBE based plant whose seismic capacity has
been determined through the SPRA process. The seismic margin of such plants can be derived
from the SPRA process.
The Canadian standards do not mandate the consideration of seismic interaction at the
design stage. This requires further evaluation for a plant not only for its BDB capacity but also
its design capacity which is likely to be affected by seismic interaction. Revision in Canadian
standards is warranted in this regard.
Canadian standards are warranted to address determination of the vertical response
spectrum in accordance with the USNRC Reg. Guide 1.208 [14] for the east coast events, rather
than the old method of considering it as two third of the horizontal response spectrum.
Amplification of the high frequency ground motion by the vertical structural elements, such as
shear walls, is required to be addressed with regard to the high frequency susceptible safety
components directly anchored to or supported by such elements.
Acknowledgments
The authors acknowledge Bruce Power, Tiverton, Ontario, Canada for providing useful resources
for writing this paper. The financial support of the Natural Sciences and Engineering Research
Council of Canada (NSERC) is greatly appreciated.
Appendix
DBE
BDB
CDFM
CLE
ENA
GMRS
HCLPF
NPP
PGA
RLE
SMA
SPRA
UHRS
Design Basis Earthquake
Beyond Design Basis
Conservative Deterministic Failure Margin
Checking Level Earthquake
East North American
Ground Motion Response Spectrum (utilized for BDB Fukushima evaluations [7])
High Confidence Low Probability of Failure
Nuclear Power Plant
Peak Ground Acceleration
Review Level Earthquake (utilized for SMA of NPP originally constructed
without a DBE in Canada)
Seismic Margin Assessment
Seismic Probabilistic Risk Assessment
Uniform Hazard Response Spectrum
References
1.
Newmark NM, Blume JH, Kapur KK. Seismic design spectra for nuclear power plants. Journal of the Power
Division, Proceedings of the American Society of Civil Engineers 1973, Vol. 99, No PO2.
2.
USNRC. Design response spectra for seismic design of nuclear power plants. Atomic Energy Commission
Regulatory Guide 1.60 Rev. 1. US Nuclear Regulatory Commission, 1973.
3.
EPRI. NP-6041-SL-Revision 1. A Methodology for Assessment of Nuclear Power Plant Seismic Margin.
Electric Power Research Institute, USA. 1991
4.
Atkinson GM, Elgohary M. Typical uniform hazard spectra for eastern North American sites at low probability
levels. Canadian Journal of Civil Engineering 2007, 34: 12-18.
5.
Dar A, Hanna JD. Beyond design basis seismic evaluation of nuclear power plants at Bruce site. Canadian
Society for Civil Engineering, 3rd International Structural Specialty Conference, Edmonton, Alberta, Canada,
2012.
6.
Canadian Nuclear Safety Commission. Regulatory Standard – Probabilistic Safety Assessment (PSA) for
Nuclear Power Plants S-294. CNSC, Canada, 2005.
7.
EPRI 1025287. Seismic Evaluation Guidance: Screening, Prioritization and Implementation Details (SPID) for
the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic. EPRI, Palo Alto, CA: 2012.
8.
Alexander CM, Baughman PD, Brown GN. Seismic margin assessment applications in Ontario nuclear power
plants. Transactions of the 19th International Conference on Structural Mechanics in Reactor Technology
(SMiRT 19), Toronto, Canada. 2007.
9.
Canadian Standards Association. CSA N289.3. Design Procedures for Seismic Qualification of CANDU
Nuclear Power Plants. CSA, Rexdale, Ontario, Canada, 1981, 2010.
10. Canadian Standards Association. CSA N289.1. General Requirements for Seismic Design and Qualification of
CANDU Nuclear Power Plants. CSA, Rexdale, Ontario, Canada, 1980, 2008.
11. Canadian Commission of Building and Fire Codes. Users’ Guide – NBC 2010 Structural Commentaries (Part 4
of Division B). National Research Council of Canada. 2010. p J-13.
12. Kinectrics Inc. Bruce B Nuclear Generating Station PRA Based Seismic Margin Assessment Phase I- Seismic
Response Characterization Report. Kinectrics Report No: K-410003-REPT-0017, Rev 00. 2012
13. Kinectrics Inc. Bruce A Nuclear Generating Station PRA-Based Seismic Margin Assessment, Phase 1 - Seismic
Response Characterization Report. Kinectrics Report No. K-410003-REPT-0021, Rev. 01, 2013.
14. USNRC. Regulatory Guide 1.208 - A Performance Based Approach to Define the Site-Specific Earthquake
Ground Motion. US Nuclear Regulatory Commission. 2007.
15. ASME. Boiler and Pressure Vessel Code. Section III, Division 1-Subsection NB, Class 1 Components. Rules for
Construction of Nuclear Facility Components. American Society of Mechanical Engineers, 2010.
16. Canadian Standards Association. CSA N285.0-08/N285.6 Series-08, CSA N285.0-12/N285.6 Series-12.
General Requirements for Pressure-Retaining Systems and Components in CANDU Nuclear Power
Plants/Material Standards for Reactor Components for CANDU Nuclear Power Plants. 2008, 2012.
17. Dar A, McKinnon B and Konstantinidis D. Seismic qualification of structures, systems and components in a
Canadian nuclear power plant. Canadian Society for Civil Engineering, 3rd International Structural Specialty
Conference, Edmonton, Alberta, Canada, 2012.
18. Atomic Energy Control Board. Regulatory Document R-77, Overpressure Protection Requirements for Primary
Heat Transport Systems in Candu Power Reactors fitted with two Shut down Systems. 1987.

Download Report